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Model improvements and validation of TerraSAR-X precise orbit determination

Hackel, Stefan and Montenbruck, Oliver and Steigenberger, Peter and Balss, Ulrich and Gisinger, Christoph and Eineder, Michael (2016) Model improvements and validation of TerraSAR-X precise orbit determination. Journal of Geodesy, 91 (5), pp. 547-562. Springer. doi: 10.1007/s00190-016-0982-x. ISSN 0949-7714.

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Official URL: http://link.springer.com/article/10.1007/s00190-016-0982-x


The radar imaging satellite mission TerraSAR-X requires precisely determined satellite orbits for validating geodetic remote sensing techniques. Since the achieved quality of the operationally derived, reduced-dynamic (RD) orbit solutions limits the capabilities of the synthetic aperture radar (SAR) validation, an effort is made to improve the estimated orbit solutions. This paper discusses the benefits of refined dynamical models on orbit accuracy as well as estimated empirical accelerations and compares different dynamic models in a RD orbit determination. Modeling aspects discussed in the paper include the use of a macro-model for drag and radiation pressure computation, the use of high-quality atmospheric density and wind models as well as the benefit of high-fidelity gravity and ocean tide models. The Sun-synchronous dusk–dawn orbit geometry of TerraSAR-X results in a particular high correlation of solar radiation pressure modeling and estimated normal-direction positions. Furthermore, this mission offers a unique suite of independent sensors for orbit validation. Several parameters serve as quality indicators for the estimated satellite orbit solutions. These include the magnitude of the estimated empirical accelerations, satellite laser ranging (SLR) residuals, and SLR-based orbit corrections. Moreover, the radargrammetric distance measurements of the SAR instrument are selected for assessing the quality of the orbit solutions and compared to the SLR analysis. The use of high-fidelity satellite dynamics models in the RD approach is shown to clearly improve the orbit quality compared to simplified models and loosely constrained empirical accelerations. The estimated empirical accelerations are substantially reduced by 30% in tangential direction when working with the refined dynamical models. Likewise the SLR residuals are reduced from −3±17 to 2±13 mm, and the SLR-derived normal-direction position corrections are reduced from 15 to 6 mm, obtained from the 2012–2014 period. The radar range bias is reduced from −10.3 to −6.1 mm with the updated orbit solutions, which coincides with the reduced standard deviation of the SLR residuals. The improvements are mainly driven by the satellite macro-model for the purpose of solar radiation pressure modeling, improved atmospheric density models, and the use of state-of-the-art gravity field models.

Item URL in elib:https://elib.dlr.de/117542/
Document Type:Article
Title:Model improvements and validation of TerraSAR-X precise orbit determination
AuthorsInstitution or Email of AuthorsAuthor's ORCID iD
Hackel, Stefanstefan.hackel (at) dlr.deUNSPECIFIED
Montenbruck, Oliveroliver.montenbruck (at) dlr.deUNSPECIFIED
Steigenberger, Peterpeter.steigenberger (at) dlr.deUNSPECIFIED
Balss, Ulrichulrich.balss (at) dlr.deUNSPECIFIED
Gisinger, Christophtum-iapgUNSPECIFIED
Eineder, Michaelmichael.eineder (at) dlr.deUNSPECIFIED
Date:3 December 2016
Journal or Publication Title:Journal of Geodesy
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In ISI Web of Science:Yes
DOI :10.1007/s00190-016-0982-x
Page Range:pp. 547-562
Keywords:atmospheric density models, radar ranging, reduced-dynamic orbit determination, satellite macro-model, solar radiation pressure
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Space System Technology
DLR - Research area:Raumfahrt
DLR - Program:R SY - Space System Technology
DLR - Research theme (Project):R - Vorhaben Infrastruktur und Unterstützung für Raumflugbetrieb (old)
Location: Oberpfaffenhofen
Institutes and Institutions:Space Operations and Astronaut Training > Space Flight Technology
Deposited By: Hackel, Stefan
Deposited On:06 Mar 2018 10:51
Last Modified:10 Jan 2019 15:48

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